E‐cigarettes in Nigeria: A scoping review of evidence

Abstract Background and Aims E‐cigarettes will continue to be a public health issue in Nigeria. To curb the growing menace of the e‐cigarette use in Nigeria through evidence‐based approach, it is crucial to first map the empirical research landscape of e‐cigarettes in Nigeria. No known study has mapped the existing empirical evidence and gaps concerning e‐cigarettes in Nigeria; hence, this scoping review was conducted. Methods This scoping review adopted the research design by Arksey and O'Malley. Four databases (PubMed, SCOPUS, CINAHL Complete, and APA PsycINFO) were searched to retrieve literature on e‐cigarettes in Nigeria. With the aid of Rayyan web application, all retrieved literature were deduplicated and screened based on the review's eligibility criteria. Only those peer‐reviewed journal papers meeting the inclusion criteria were included in the review. Relevant data from the included papers were charted, collated, and summarized. Results A total of six papers were included in this review. The reviewed papers reported a lifetime prevalence of e‐cigarette use (or vaping) ranging from 5.8% to 19.8%, with a current e‐cigarette use prevalence of 11.8%, among different population groups in Nigeria. The major determinants of e‐cigarette use, as reported in these articles, include being a youth, having a health condition, severe anxiety, tobacco use, peer influence, and current alcohol use. Dry mouth and oral lesions (gingival inflammation and oral ulcers) were also identified to be the medical conditions associated with e‐cigarette use in Nigeria. Lastly, one of the included papers identified a lack of clear regulation on e‐cigarettes in Nigeria. Conclusion There is an urgent need for more scientific investigations on the sociodemographic, economic, health, and regulatory landscape of e‐cigarettes in Nigeria, as robust empirical evidence is needed for the effective planning, implementation, and evaluation of evidence‐based policies and interventions on e‐cigarettes control and regulation in Nigeria.

Electronic cigarettes (e-cigarettes), also referred to as electronic nicotine delivery systems (ENDS), are electronic or battery-operated devices that vaporize a liquid (typically consisting of propylene glycol and glycerol, with or without nicotine and flavors) into an inhalable aerosol. 1 The liquid is contained in disposable or refillable cartridges or reservoirs. 1 Vaping, a process of using an e-cigarette produces feelings comparable to smoking a combustible cigarette both in taste and similar pleasures that smoking generates. 1Newer e-cigarette devices have evolved in shape and variety, often looking like pens and other contemporary appearances compared to older versions that resembled cigarettes.Hence, e-cigarettes are heterogeneous in terms of devices, products, e-liquids, and product components. 11][12] Introduced around the early 2010s, e-cigarettes gained popularity as a perceived safer alternative to traditional tobacco products.However, their rapid adoption, particularly among youth demographics, has raised concerns about potential health risks and regulatory challenges. 13,14Monitoring e-cigarette trends helps to assess patterns of use and misuse and facilitate proactive regulatory policies. 15Among young adults (aged 19-30 years) in the United States, e-cigarette use prevalence in 2021 was 21.8% (vaping nicotine) and 18.7% (vaping marijuana) reflecting over a 100% increase when compared to 2017 estimates. 12In a 2021 survey among adults in Canada, e-cigarette ever-use prevalence was 48% (aged 20-24 years), 29% (aged 15-19 years), and 13% (aged ≥25 years). 16Among all adults in Great Britain, e-cigarette prevalence has remained constant since 2015; however, 2017-2018 prevalence estimates account for 5.4% to 6.2% for all adults. 17In Southeast Asia, the prevalence of current e-cigarette users varies from 3.3% (Thailand) to 11.8% (Indonesia). 180][21] This is important as critical brain regions do not reach full maturity until individuals are in their early or mid-20s. 19milarly, an essential component of e-cigarette use is recognizing the appropriate time to quit.The prefrontal cortex, which governs judgment, decision-making, behavior, and emotion control, continues to undergo development throughout adolescence.4][25] Diverse perspectives exist regarding the potential harm reduction value of e-cigarettes for adults, particularly for combustible cigarette smokers. 8,9Nevertheless, there is widespread agreement on the necessity to safeguard young people from the potential risks associated with this emerging technology. 26cent evidence has highlighted potential environmental concerns associated with e-cigarette use, 27 including mixed evidence regarding potential health risks.5][36] In the interim, significant fatality was recorded from "e-cigarette or vaping product use associated lung injury" (EVALI) in the United States in 2019 when e-cigarette e-liquids were used in combination with marijuana oil leading to the deaths of over 65 people who vaped this product including 2800 hospitalizations. 37Furthermore, conflicting findings exist among published evidence between 2018 and 2020 regarding e-cigarette effectiveness as a tool to quit smoking.[45] Despite varying evidence to support or prevent e-cigarette use, it continues to appeal to several consumers-mostly teenagers and young adults.48,49 Ecigarette sales have deeply penetrated developed economies like the United States. 502][53] Nigeria, a low-middle-income country with a vast youthful population is a prime target for this expanding ecigarette market.
The use of e-cigarettes in Nigeria has been fueled by numerous factors including aggressive marketing strategies, accessibility, and the allure of trendy vaping culture.Amidst limited tobacco control policies and enforcement mechanisms, the vaping industry expanded rapidly, with a plethora of brands and flavors flooding the market.Despite the absence of comprehensive national data, anecdotal evidence suggests a growing prevalence of e-cigarette use among Nigerian youths, with concerns about nicotine addiction and long-term health implications. 13,14Additionally, the lack of regulation has facilitated the proliferation of substandard products and counterfeit imitations, aggravating health risks.To strengthen governmental commitment towards robust policy formulation and funding of evidence-based prevention programs, there is a need to contextualize the burden of e-cigarette use in Nigeria.[56][57][58][59][60][61][62] However, no known study in Nigeria has charted, collated, and summarized all research evidence, as well as identified inherent gaps found in existing literature.Therefore, this study aims to conduct a scoping review to address these concerns.The findings from this review will provide relevant insights into the current epidemiology and impact of e-cigarette use in Nigeria especially among at-risk populations (adolescents and young adults) as well as provide directions for future risk and market surveillance, research on health impacts, policy responses, evidence-based prevention programs, and stakeholders engaged in clinical and/or public health practice.

| Review design
The design of this review was based on the stepwise procedure, developed by Arksey and O'Malley, for conducting scoping reviews. 63Also, we followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews guidelines (PRISMA-ScR) in reporting this review. 64

| Research question identification
This study seeks to answer this principal research question: What scientific evidence exists on e-cigarette or vaping in Nigeria?However, to obtain answers on some pertinent areas, the principal question was divided into six subquestions:

| Literature search
On January 27, 2023, a systematic search was used to retrieve relevant literature from the PubMed, SCOPUS, CINAHL Complete, and APA PsycInfo databases.For the achievement of robust literature selection, the search for studies in the listed electronic databases was developed from the appropriate research terms and best fit to answer the research questions developed for this scoping review.This search was conducted using relevant terms and synonyms ("vape" OR "vaping" OR "e-cigarette" OR "electronic nicotine delivery") AND ("Nigeria") obtained from the Medical Subject Heading (MeSH) dictionary and Thesaurus, and with the aid of Boolean operators ("AND" and "OR"), to retrieve all relevant literature published from inception till December 2022.Supporting Information S1: Tables S1-S4 show the search strategy used for the search from each of the selected databases.Also, we did a manual search of the reference lists of the literature that were included in this review to further retrieve any other eligible literature that were not identified through a database search.
Only those publications that met the following criteria were included in the review: • papers published in refereed journals; • journal papers of any type (letters, editorials, comments, original research articles, review articles, etc.); • journal papers reporting empirical evidence concerning ecigarettes or vaping in Nigeria; and • journal papers with accessible full text.
The citations of the literature obtained from the database search were exported into the Rayyan software for deduplication.
After deduplication, the residual literature was screened for inclusion in the review (Figure 1).The screening process was twostaged and done by two reviewers (one medical doctor [O.E. A.] and one dental surgeon [K.K. K.], both with specializations in the field of public health).The review's inclusion criteria guided the screening process, with the first stage involving the title and abstract screening while the second stage involved full-text screening.Only those articles that met the inclusion criteria were included in the review.A third reviewer (O.D. A.) was involved in situations where there were conflicts in the decisions of the two reviewers (O.E. A. and K. K. K.).Additionally, there was no ambiguity encountered in interpreting abstracts during the screening process; hence, no author was contacted to provide clarification or additional information on the screened literature. 65

| Quality appraisal
The Mixed Methods Appraisal Tool (MMAT) 2018 version was used to appraise the quality of the included literature, 66 and two reviewers (O.E. O. and K. K. K.) were involved in the appraisal process.The MMAT uses a set of seven questions per research design to appraise empirical research literature.This research design appraisal tool could assess qualitative study designs (ethnography, phenomenology, grounded theory, etc.), quantitative randomized controlled trial designs, quantitative nonrandomized study designs (nonrandomized controlled trial, cohort study, case-control study, and cross-sectional analytical study), quantitative descriptive study designs (case series, case report, etc.), and mixed methods study design (convergent study, sequential exploratory study, and sequential explanatory study). 66For each of the questions in the MMAT, there are three possible answers: "Yes," "No," and "I can't tell." 66In the appraisal process, a reviewer's response of "Yes" was awarded 1 point, a response of "No" was awarded zero point, and a response of "I can't tell" was awarded zero point.Since empirical research literature can only be graded with seven questions, a 7-point scale was therefore used to grade the appraisal outcome.
Appraised literature with a grade of 4/7 points or above were considered to be of "above average" quality while those with a grade of 3/7 points or below were considered to be of "below average" quality.However, all included literature were reviewed in this scoping review regardless of their quality appraisal outcomes (Supporting Information S1: Tables S5-S7).

| Collation, summarization, and presentation of the charted data
The charted data are collated and summarized using a narrative synthesis approach.The summarized data are thereafter presented in texts and a table (Table 1).Out of these literature, six were duplicates and were deleted.The titles and abstracts of the remaining seven publications were screened, and one nonrelevant publication was excluded.The full texts of the remaining six literature were screened, and all were relevant and included in the scoping review.In addition, the reference lists of the included literature were manually searched but no eligible literature was found (Figure 1).

| Quality appraisal outcomes
All the included literature were appraised, and they had a grade of 6/ 7 points and above; hence, they were all considered to be of aboveaverage quality (Supporting Information S1: Tables S5-S7).

| Publication trend by year
All the included literature were journal papers published within the last 6 years, of which one was published in 2017, 67 one in 2020, 62 one in 2021, 54 and three in 2022 59,61,68 (Table 1).

| Publication type
All the included papers, of which five 54,59,61,62,67 were original research articles while one 68 was a letter to the editor (Table 1).

| Study design
None of the included papers adopted an experimental or quasiexperimental research design.However, five papers 54,59,61,62,67 adopted a quantitative cross-sectional study design while one 62 adopted a qualitative study design (Table 1).

| Study location
All the included papers reported the specific geographical location in Nigeria where their study data were collected, except for the study by Erinoso et al. 68 which referred to no specific Nigerian location.
Among the remaining five papers, two 54,62 collected data from Lagos, one 67 collected data from Lagos and Abuja, and two 59,61 collected data from all 36 states in Nigeria including the Federal Capital Territory (Table 1).

| Study instrument
All the included papers specifically reported their study instrument, except for the one by Erinoso et al. 68 which was not clearly defined.
Of the remaining five papers, one adopted the use of a highperformance liquid chromatography machine for data collection, one adopted the use of ICONIT (full meaning not stated in the reviewed article) software, three adopted the use of a questionnaire, one adopted the use of a question guide, and one adopted the use of an audio recorder (Table 1).

| Awareness and knowledge of e-cigarettes in Nigeria
Two papers provided evidence of the awareness and knowledge of ecigarettes in Nigeria.One of the papers, by Erinoso et al. 54 utilized a quantitative approach while the other paper, by Osibogun et al., 62 utilized a qualitative approach with both papers investigating a total of 969 adolescents and young adults.Only the study by Erinoso et al. 54 reported awareness of e-cigarettes as 59.7%.

| Prevalence of e-cigarette use in Nigeria
Three papers provided evidence of the prevalence of e-cigarette use in Nigeria, and all three studies surveyed a combined population of adolescents and young adults. 54,59,61All three papers reported different lifetime prevalence rates which ranged from 5.8% to 19.8%.
Also, it is noteworthy that only one paper, by Erinoso et al., 54 reported the prevalence of current use (i.e., use within the past 30 days) of e-cigarettes in Nigeria.In their study, 11.8% (6/51) of participants with a lifetime history of e-cigarettes were found to be current e-cigarette users.

| Health implications of e-cigarette use in Nigeria
Only one paper 59 provided evidence of the health implications of ecigarette use in Nigeria.This paper identified oral lesions (gingival inflammation AOR: 1.51, 59 oral ulcers AOR: 1.89), 59 and dry mouth (AOR: 1.96) 59 as some of the health implications of e-cigarette use in Nigeria.

| Public health interventions (including policy) on e-cigarettes and vaping in Nigeria
None of the included papers provided evidence of public health interventions (including policy) on e-cigarette use and vaping in Nigeria.

| Other findings on e-cigarettes and vaping in Nigeria
Two papers 67,68 provided other findings on e-cigarettes and vaping in Nigeria.One paper, by Omaiye et al., 67 reported on counterfeit electronic cigarette refill fluids purchased from online stores in Abuja, Nigeria labeled 0 mg/mL of nicotine but contained nicotine in quantities ranging from 3.7 to 20.4 mg/mL following analysis of the e-cigarette refill fluid.The second paper by Erinoso et al. 68 reported on the online retail environment for electronic nicotine delivery systems (ENDS) in Nigeria.This paper stated that seven out of 20 (35%) online retail stores surveyed exclusively sold ENDS products and e-liquids.A majority (75%) of the online retail stores surveyed in this paper provided access to PODS sales while over 65% of the eliquid products sold provided no label information regarding the nicotine concentration of the e-liquids or age restrictions/advisory regarding its use.

| DISCUSSION
This scoping review is believed to be the first study to broadly collate all existing information available on e-cigarette in Nigeria, and the identified findings are noteworthy and insightful for public health planning, research, practice, and policy and/or regulation formulation.
Based on this review's findings, it can be noted that most of the population groups that were surveyed in Nigeria were adolescents and young adults (ages 11-35 years).Similarly, the identified lifetime prevalence of e-cigarette use ranged from 5.8% to 19.8% while the identified prevalence of current use of e-cigarettes was 11.8%.The e-cigarette use prevalence range reported in this review is lower than that reported in a South African study, where a prevalence of 37% ecigarette use was reported among a comparable population group. 69mulatively, this shows that e-cigarette use is becoming a popular practice among adolescents and young adults in Africa.
According to the 2012 National Bureau of Statistics in Nigeria, the population of individuals aged 15-35 years in Nigeria was estimated to be about 64 million people; this represents about 36.8% of the productive workforce population of Nigeria. 70As earlier described (see the introduction section of the full text), early-onset ecigarette use could facilitate the use of other illicit or psychoactive substances. 23,24Upon leaving high school and gaining more independence, whether in college or as employed adults, individuals might be exposed to e-cigarette use without the protective framework provided by family and school resulting in profound consequences including use/high-risk use of other substances (combustible cigarettes, heroin, smoking marijuana, and prescription stimulants used nonmedically).Consequently, this may heighten the frequency of drug use, misuse, and addiction, leading to harmful health outcomes, particularly chronic diseases (HIV and hepatitis B and C). 28,71A significant proportion of older adults who meet the criteria for a substance use disorder began using substances during their teenage and young adult years. 22Furthermore, substance misuse is associated with risky sexual behaviors, exposure to violence, violent crimes (homicides and rape), and increased risks of mental health issues and suicide. 72These deleterious outcomes have profound negative impacts on college education enrollment, engagement, retention, and success of Nigerian students who are predominantly adolescents and young adults 55 thereby highlighting the urgency of addressing vaping practices among this at-risk population group.
Reports in other climes have shown that e-cigarette use among tertiary institution students could lead to future traits of impulsivity, risky behaviors, and increased use of other illicit drugs like opioids, cocaine, and other stimulants or hallucinogens which may result in anxiety, low self-esteem, and defiant behaviors including gambling. 23These outcomes may impact significantly the psychological and socioeconomic contributions of youths to national growth and development especially in a country like Nigeria.
Furthermore, mental health outcomes including depression and suicidal ideation have been associated with adolescents' e-cigarette use. 73Overall, the above-identified risks lend insights into the potential dangers associated with adolescent/youth e-cigarette use on student retention, drop-out, and future career development within higher education and/or workplace settings in Nigeria.
Clearly, from the available empirical research data obtained in this scoping review, there was limited information to highlight the prevalence trends of e-cigarette use in Nigeria.However, this paucity of data is not limited to Nigeria alone, such was also observed in other sub-Saharan African countries. 74Hence, it would be highly beneficial if research efforts were geared towards continuous data collection on e-cigarette use in Nigeria and other sub-Saharan African countries as well.By so doing, this would help inform policy direction and predict evidence-based interventions to enhance e-cigarette cessation, addiction prevention, and harm reduction, especially within the at-risk populations, more especially the adolescent and young adult population group.Additionally, the impact of the COVID-19 pandemic continues to heighten e-cigarette use 37 with a proportional increase in adolescent and young adults' engagement in risky behaviors.Hence, it is paramount to continuously collect relevant data to inform policy direction that would limit the risk indices in atrisk users.Going forward, this can be achieved in Nigeria through the establishment of a national database to monitor future trends in ecigarette use and how it impacts the Nigerian population, especially its productive workforce.
Notably, this scoping review also identified the determinants of e-cigarette use among the Nigerian population, and being an older youth, having a health condition, severe anxiety, previous or current tobacco use, peer influence, and current alcohol use were the major determinants identified. 54,61,62In the course of comparing our findings with those that have been reported in other African countries, through an extensive literature search, we found that no other known study was found to have exclusively reported the determinants of e-cigarette use in Africa. 69,75 Additionally, this scoping review identified the health implications of e-cigarette use among the Nigerian population.Two of the included papers reported how vaping could lead to smoking. 61,62ile this finding demands further exploration, it portrays grave danger to the success of existing tobacco legislation in Nigeria.
Consequently, there is a need for researchers, public health experts, and policy analysts to further investigate these trends and provide timely insights critical to enhancing policies aimed at smoking cessation in Nigeria.Furthermore, this review also identified other health implications of e-cigarette use in Nigeria which include oral lesions (gingival inflammation, oral ulcers), lung conditions, and liver disease.However, the implications identified in these studies were not exhaustive.For example, several studies outside Nigeria have identified that e-cigarette use can cause e-cigarette, or vaping use-associated lung injury (EVALI). 37,76To broadly understand the diverse health implications of e-cigarette use in Nigeria, its specific causes, and future complications of these conditions, clinicians, public health experts, researchers, policy analysts, and government agencies need to develop and formulate strategic coalitions that will bolster effective and well-coordinated approaches to collect relevant data and design evidence-based programs to reduce e-cigarette use and its continued attendant effect on the human health.
It is noteworthy that this review also identified some empirical evidence on issues concerning e-cigarette regulation in Nigeria. 68ndings suggest that there are no effective laws or policies tailored to regulating e-cigarettes in Nigeria.In the reviewed study, 68 it was found that some e-cigarettes sold in Nigeria had misleading or insufficient information on their nicotine content.Aside from this study, 68 there is no other study that has investigated issues related to e-cigarette regulations in Nigeria; hence, there is a need to expand on the existing literature in this area.Notably, some studies outside Nigeria have examined regulations of e-cigarettes [51][52][53] including the geospatial spread of vape shops and its relation to e-cigarette use, especially among adolescents and young adults. 77,78Considering the huge relevance of these studies to policy formulation and implementation, it is highly recommended that similar studies be conducted in Nigeria.This area of future research should be considered a priority as e-cigarette regulation and laws may predict the patterns of ecigarette use, its availability, advertising, marketing, and distribution to potential end-users.A key area of public health significance is ecigarette advertising, marketing, and sponsorship.Several studies outside Nigeria have reported the impact of e-cigarette advertising and marketing on attempts to quit vaping [48][49][50] and the potential to encourage individuals who have quit smoking to start vaping. 79,80nce, more studies are needed to provide scientific evidence on ecigarette advertising, marketing, and sponsorship in Nigeria, as such evidence is pivotal for proper planning, implementation, and evaluation of policies on e-cigarettes in Nigeria.

| CONCLUSION
This scoping review has described available information on vaping practices in Nigeria while highlighting several limitations on ecigarettes and vaping research in Nigeria especially as it relates to its knowledge and awareness, prevalence, determinants, health implications, program or policy interventions, and regulations.This review has identified determinants of vaping in Nigeria which include being a youth, having a health condition, severe anxiety, tobacco use, peer influence, and current alcohol use.There is limited information to highlight the trends of e-cigarette prevalence in Nigeria.There is no evidence of a national strategy or regulations to tackle rising ecigarette use in Nigeria nor are there available evidence-based programs to address or limit its use.This scoping review highlights the need for more evidence on the knowledge, awareness, and prevalence of vaping in Nigeria.There is a need for future research to better understand the complex interplay of determinants that affect vaping, the need to advance specific evidence of the health implications of vaping, and evidence-based clinical and public health strategies to limit them.There should be more coordinated and virile approaches towards e-cigarette regulation, and other policies that may impact vaping, encourage vaping cessation, prevent addiction, and reduce harm, especially among the at-risk e-cigarette users in Nigeria.

Subquestion 1 :Subquestion 6 :
What scientific evidence exists on the awareness and knowledge of e-cigarette or vaping in Nigeria?Subquestion 2: What scientific evidence exists on the prevalence of e-cigarette use in Nigeria?Subquestion 3: What scientific evidence exists on the determinants of e-cigarette use in Nigeria?Subquestion 4: What scientific evidence exists on the health implications of e-cigarette use in Nigeria?Subquestion 5: What scientific evidence exists on the public health interventions (including policy) on e-cigarette or vaping in Nigeria?What other scientific evidence exists on ecigarette or vaping in Nigeria?

Following
rigorous deliberations and standardization, three reviewers (O.E. A., O. D. A., and K. K. K.) collaborated to extract data from the included literature.From the included literature, the following data were extracted: citation details (names of authors and the year of publication), journal paper type, study design, study population size and characteristics (gender distribution, age distribution, and other sociodemographic features), study location, study findings, and conclusions.
included papers investigated diverse populations.Only one paper investigated e-cigarette refill fluids, one investigated retail stores, and four investigated a combined population of adolescents and young adults.In total, 3839 persons aged 11-35 years, 29 ecigarette refill fluids, and 20 retail stores in Nigeria were investigated Preferred Reporting Items for Systematic Reviews and Meta-analyses.Summary of the included literature.
T A B L E 1Abbreviation: SD, standard deviation.